Abstract: A method for an engine may comprise, in response to an EGR valve closing, determining an EGR oxygen content, and purging an EGR system when the EGR oxygen content is less than a threshold oxygen content.

Abstract: A vacuum assist system attaches to an intake line and an intake manifold of an internal combustion engine having a throttle. The vacuum assist system includes a venturi valve, a reservoir, and a proportionally controlled valve. The proportionally controlled valve is movable between an open position and a closed position. The proportionally controlled valve moved to the open position when the throttle is in the partially open position such that air is flows from the inlet to the intake manifold, from the inlet to the venturi valve, from the venturi valve to the intake manifold, and from the reservoir to the venturi valve. The proportionally controlled valve moves to the closed position when the throttle is in the almost-closed position such that air flows from the inlet to the intake manifold via the intake line and from the reservoir to the intake manifold to reduce the pressure within the reservoir.

Abstract: An apparatus and method for improving vehicle performance by application of pneumatic boost to vehicle engines, including diesel engines having at least one turbocharger supplying air to the engine, in a manner which increases engine torque output while minimizing the potential for exceed various operating limits to the maximum practicable extent. The vehicle's pneumatic booster system controller implements strategies for shaping the rate of the air injection during a boost event, tailoring the air injection to obtain maximum engine torque output while respecting the operating limits, by controlling the timing, duration, quantity and/or injection pattern during a boost event to achieve a refined distribution of compressed air injection over the course of the boost event to provide desired engine torque output and fuel efficiency while minimizing the potential for exceeding a wide variety of operation limits, regulatory, engineering and passenger comfort limits.

Abstract: Fuel delivery system for an internal combustion engine comprising a method and apparatus for generating and delivering a homogeneous charge with a variable fuel/air ratio which relies on fuel-absorbent, air-permeable evaporative wick membranes in a primary mixing region to which a portion of thermally-regulated air from an air dividing region has come. A single moving control element is used to control the quantity of in-rushing air in the primary mixing region, and therefore the amount of fuel rich air produced in this primary mixing region, and at the same time this single moving control element modulates both the quantity of fuel rich air and the quantity of regular fuel-free combustion air which are brought together in a secondary mixing region where they combine in the desired ratio to form a homogeneous charge with a variable fuel/air ratio. The use of a single moving control element allows extremely economical construction.

Abstract: A method is provided for controlling an engine having an intake manifold and an outlet control device coupled to the manifold for controlling flow exiting the manifold and entering at least one cylinder of the engine. The engine further includes an inlet control device for controlling flow entering the manifold. The method includes providing an engine command; calculating a desired cylinder charge based on said command; and adjusting the outlet control device to provide said desired cylinder charge. The engine command may be, for example, a driver command, such as a driver torque command. Further, the outlet control device may be implement in with a variety of mechanisms. For example, in one embodiment the outlet control device is a valve of the engine having a variable lift. In one embodiment the outlet device is a valve having variable timing. Likewise, the inlet device may be adjusted in response to a variety of parameters.

Abstract: In this invention, there is provided a method for reducing NOx emission from an internal combustion engine designed to produce a given amount of power and a method for improving fuel efficiency by providing an intake stream of oxygen-enriched air and keeping the amount of power output the same so that the combustion temperature in the engine is lower.

Abstract: Flow passage lines are used to connect the float chamber of a conventional carburetor both to the engine's intake and exhaust manifold. The gas flow produced by the exhaust manifold provides a continuous source of positive pressure to the float chamber, while the engine's suction and the corresponding vacuum in the intake manifold provide a continuous source of negative pressure. The flow rates in the positive pressure line and in the negative pressure line are regulated by means of two control solenoid valves. The pressure in the float chamber reflects the net impact of the positive and negative pressures transmitted trough the lines. The solenoid valves are responsive to a control signal generated by an electronic circuit as a function of deviations in the oxygen content of the exhaust gases from a desired set point. The ambient pressure in the float chamber is either increased or decreased as the oxygen sensor indicates that either a lean or a rich fuel mixture is being combusted in the engine.

Abstract: The system for controlling the air/fuel mixture introduced into a lean burn engines includes a fuel/air mixing carburetor that is connected to the intake conduit to the engine and an air by-pass conduit that is also connected to the intake conduit. The main throttle valve is located downstream of the connection between the carburation conduit and the by-pass conduit so that mixing of the carbureted fuel/air mixture with the by-pass air occurs upstream of the main throttle valve. Accordingly, the main throttle valve does not control the air/fuel ratio but rather controls the quantity of fuel being introduced into the engine. The by-pass throttle valve may be controlled by an oxygen sensor in the exhaust system or by a fuel sensor in the intake system, when operating on natural gas, gasoline, hydrogen or alcohol fuel, as desired.

Abstract: A control system for an internal combustion engine controls an amount of auxiliary air supplied to the engine in the following manner: Concentration of evaporative fuel contained in a gas purged from an evaporative emission control system into an intake passage of the engine is calculated based on a purging flow rate estimated based on operating conditions of the engine, and an output from a flowmeter arranged in the evaporative emission control system. A volume of the gas purged over a predetermined time period is calculated based on the output from the flowmeter. A parameter indicative of dynamic characteristics of the gas is calculated based on operating conditions of the engine. An amount of air contained in the purged gas drawn into a combustion chamber of the engine is calculated at least based on the concentration of evaporative fuel, the volume of the purged gas, and the parameter indicative of dynamic characteristics of the gas.

Abstract: An air-fuel ratio feedback control apparatus for a gas engine. A mixer mixes intake air and a fuel gas. A subsidiary supply path supplies at least one of the intake air and the fuel gas downstream of the mixer. Oxygen concentration sensors detect a concentration of oxygen in an exhaust gas; and operation condition detectors detect operating conditions of the gas engine. A basic amount setting unit sets a basic amount of at least one of the intake air and the fuel gas supplied through the subsidiary supply path. A correction amount setting unit sets a correction amount proportional to a total fuel gas supply rate, and a control amount setting unit for setting a control amount of at least one of the intake air and the fuel gas supplied through the subsidiary supply path by adding the basic amount and the correction amount together, whereby the air-fuel ratio of the gas engine can be controlled at a desired value even when a bypass supply ratio of the fuel gas varies.

Abstract: A pollution or emission control system for retrofitting on older vehicle engines includes a catalytic converter with an in-built oxygen sensor for mounting in the exhaust line, and a supplemental air input line containing a control valve for connection to the engine intake manifold to control the amount of air supplied to the engine. A computer monitors the oxygen sensor output and the engine speed, and controls opening and closing of the control valve according to the detected conditions. The computer also controls the speed at which the valve is opened or closed dependent on the engine speed and optionally the engine temperature, so that the valve can be closed faster at slower engine speeds and opened faster at higher engine speed. The computer is additionally capable of producing diagnostic telemetry, both digital and analog, to assist installation of the invention and test for proper operation once installed.